Why do we have tears while crying?

We humans are emotional creatures and this is what separates us from other living beings. Emotions creates all sorts of feelings which can bring us joy , sadness , irritation, frustration , jubilation etc. Among these , Happiness and distress tends to be on top of the list. We all cry while in pain or distress. But have you ever pondered upon the fact that why do we get tears while crying. How does our eyes get to know that it has to shed tears whenever we are emotional. Continue reading to know more about it.

What are tears?

Tears are created by lacrimal gland which are located between the eyeball and eyelid. A tear consist of three layer which includes oil , water and mucus. Water content in tear is maximum while the oil ensures in keeping the eyes moist. A tear is produced in human eye irrespective of whether we cry or not. They get drained off through the tiny openings in our eyelid and goes out as part of our nasal fluid.

Types of Tears

There are three types of tears – Basal , Reflex and Emotional.

Basal are the ones which are produced in the eyes at all times and help to nourish and moist our eyes.

Reflex are produced due to protective actions against external particles or irritants which is why eyes get wet while cutting onions.

Emotional comes out while we are sad or happy. They are dependent on human emotions.

How does our tear producing system activate?

Just as with any other body organ, brain has a direct link which instructs it when to produce tears. A part of human brain called the limbic system takes care of all human emotions. Whenever we are emotional, brain sends signals to the lacrimal gland(which produce tears) via neurotransmitter known as Acetylcholine & instructs it to start producing tears. Acetylcholine is an organic chemical released by nerve cells used in sending signals to different body cells.
The composition of emotional tear is high on proteins. It contains prolactin and leucine enkephalin which is a natural pain killer. Thats the reasoning behind why we feel better after crying.